Apparatus for undisturbed overburden sampling



July 2, 1946. H. L. JOHNSON 2,403,002

APPARATUS FOR UNDISTURBED OVERBURDEN SAMPLING Filed March-6, 1940 4Sheets-Sheet 1 Fly. 1

ATTORNEY.

July 2, 1946. JOHNSON APPARATUS FOR UI ID'.[STURB]:'1D OVERBURDENSAMPLING Filed March 6, 1940 4 Sheets-Sheet 2 L... 4 I h 30 INVENTOR.'f/en Lrjbknsrm Q ATTORNEY.

July 2, 1946. H. L. JOHNSON ,00

APPARATUS FOR UNDISTURBED OVERBURDEN SAMPLING Filed March 6, 1940 4Sheets-Sht 3 IIIIHIIIII Henry .L.J 07zns0n y 1946- H. L. JOHNSON A A 2,

APPARATUS FOR UNDISTURBED OVERBURDEN SAMPLING sampling operations.

Patented July 20, 1946 UNITED STATES PATENT omos APPARATUS roeUNDISTURBED OVERBURDEN SAMPLING Henry L. Johnson, Denison, Tex.Application March 6, 1940, Serial No. 322,545

(Granted under the act of March 3, 1883, as

This invention described herein may bemanufactured and used by or forthe Government for v governmental purposes, without the payment to me ofany royalty thereon.

This invention relates generally tothe art ofamended April 80, 1928; 370'0. G. 757) date the conditions met in the natural deposits belowthe'wat'er table, and to provide for the renewal of shoe cutting teeth,when they become worn, dull, or broken, and the extracting of the samplein such manner that it is undisturbed.

Another object of theinvention is to provide a sampling device which iof simple, economical, and durable construction, and one which may beeasily and quickly attached to standard drill rods and operated with astandard rotary-type coredrilling rig of suitable size, and easilycleaned.

Another object of the invention i to provide a means of carrying awaycuttings by use of a circulated mud or viscous and thixotropic fluids,which form a filler and support the drill hole walls to prevent cavingand contamination oi the sample, and eliminates the needof casing tomaintain the hole in an open condition. durin r A further object of theinvention is to provide means for obtaining a continuous and undisturbedsample uncontaminated by drilling mud or cuttings of overburden orsimilar materials, from deposits of such materials in situ.

' The invention which forms the subject matter of this applicationrelates. to means for sampling gravels, sand, silts, and mixturesthereof, in which the drilling mud, or viscous and thixotropic fluid, isintroduced and .clrculated in the drill hole and sampling device in sucha manner as to carry away the cuttings from the materials being cut bysuspension in said mud or fluid without contaminating the sample. I

Certain classes of overburden or similar materials in situ are verydimcult to sample. The difflculty arises in deposits below the naturalwater being sampled to overcome this dimculty.

The improved apparatus for efiecting sampling operations may be utilizedin the following forms of engineering work:

Sampling of natural foundation materials in situ. for all types ofstructures; fOr foundation studies; and

Sampling .of materials placed in earth'dams, dam levees, and dikes fortest purposes.

Referring. more particularly to the accompanying drawings in whichcorresponding P rts are indicated by similar reference characters:

, Figures 1 and 2, together, comprise a side sectionalized view of thesampling device.

Fig. l is a side, centrally sectionalized elevation of the top portionof the sampling .device; and fits above Fig. 2 which is a side centrallysectionalized elevation of the bottom portion of the sampling device: a

Fig. 3 is an end elevation of a standard rota ytype core-drilling riprovided with a pump for circulating the drill mud .or viscous andthixotropic fluid, and fitted with standard drill rod connecting thedrill rigwi-th the sampling device;

and

Fig. 4 is an enlarged sectionalized view or the sampler, and indicatesthe circulation of the drill mud in the sampler, all shown in Fig. 3.

The sampling device consists of an outer drill barrel head I, withthreaded hole at 4 to take standard drill rods, and an outer core barrel20, which are coupled to an inner barrel head 18 and an inner barrel Itby means of a hollow spindle shaft H to permit the inner barrel is toremain stationary while the outer barrel 20 is rotated. The inner barreli9 is equipped with a L check valve 22 having a soft rubber facing 23toprovide a tight seal, a valve seat 24 having valve guides 25 welded tothe valve seat 24 as shown at M, a sample catcher ring 3| fitted withflexible springs 32, a sample cutting shoe 29, and

rotary drill forces the sampler downward into table which are ina quickor semi-quick conditi ne sampling device may be fitted with the materialbeing sampled and the drill imparts a rotary motion to the outer barrel2!! and it cuttingshoes of variable lengths to accommo as shoe 28 andcutting teeth '30 while drilling mud or fluid is being circulatedthrough the sampler via the hollow drill rods by means of a slush pump.In operation, the device is forced downward into the material to besampled while the drill is rotating and drilling fluid or mud iscirculated. l

The downward thrust of the drill rod is transmitted through the outerbarrel headto the inner barrel l9 and the sample cutting shoe 29 bymeans .of the hollow spindle shaft I5 attached to the inner barrel headI6 and secured by lock nut I8. To permit the inner barrel l9 and thespindle shaft Hi to remain stationary while the outer barrel 20 isrotating, the spindle shaft is equipped with a ball thrust bearing 8 anda bronze ring bearing Ill. To prevent water, drilling fluids, grit,etc., from gaining access to bearings 8 and III, the outer barrel head iis recessed to take four felt grease retainers 9 which fit around theupper end of the hollow spindle shaft i5, and is equipped with a packingbox l4, containing packing l3, which is automatically compensated forwear by means of packing washer I2, upon which the coil spring exerts acontinuous pressure. The outer barrel head I is also provided with agrease port 5 which is closed by stud bolt 6 seated against a copper'washer l to make a tight seal.

When a sample is taken, the protruding sample cutting shoe 29 enters thematerial being sampled and is prevented from rotating by its downwardpressure and friction between the shoe and the material, thus causingthe inner barrel l9 and all of its parts to remain stationary. Meanwhilethe outer barrel 20, its shoe 28 of varying lengths depending on thematerial cut, and the cutting teeth 30 are rotated and drilling mud orfluid circulated to remove material through which the sample cuttingshoe 29 has passed. The drilling mud or fluid is pumped down the hollowdrill rods and enters the sampler by way of the inlet ports 3-in theouter barrel head I and passes downward between the inner barrel l9 andouter barrel 20 and their shoes 29 and 28, escaping under the edge ofthe outer barrel shoe 28, returning upward to the surface between theouter barrel 20 and the side of the drill hole, carrying the materialloosened by the cutting teeth 30 up with it.

As the sampler penetrates the material being sampled, the sample cuttingshoe 29 cuts the sample, which enters the shoe 29 and passes upwardthrough the core catcher ring 3|, forcing the springs 32, which retainthe sample in the sampler when it is extracted from the hole, to openand allow the sample to pass up into the thin sheet metal sample tube21, which is inserted in the inner barrel l9 prior to inserting the corecatcher ring 3| with its attached springs 32 and attaching the samplecutting shoe 29 preparatory to taking the sample. As the sample entersthe inner barrel, the drilling fluid entrapped therein, when thesampling device is lowered into the hole which is kept full of drillingfluid to prevent caving, is forced upward through the valve seat 24inserted in the inner barrel l9 and held in place by studs 26, liftingthe check valve 22 which is faced with soft rubber 23 to provide a tightseal when the valve is closed.

The check valve is kept in proper alignment by r the guides 25 which arewelded 2| to the valve seat 24.

After passing through the valve, the drilling fluid escapes from theinner barrel l9 outlet ports 2 into the drill hole above the sampler.

Drilling muds or fluids of a thixotropic nature are used because theyplaster and support the sides of the hole to prevent caving and therebyeliminate the need of casing, and because by their consistency theyreadily carry cuttings to the surface and do not penetrate the materialsbeing sampled for more than a fraction of an inch.

For-facilitating assembly and disassembly, the inner barrel head I6 isprovided with spanner wrench sockets H.

In operation the undisturbed overburden sampler described above isactuated-by means of a rotary core drill rig using hollow drill rods andequipped with a suitable slush pump. One type of such rig and thegeneral setup of the apparatus is diagrammatically shown by Figure 3.

In practice the top three or four feet of material are sampled with anordinary drive sampler, the hole 34 reamed out and a short length ofcasing 33 inserted to protect the top of the hole 34, The undisturbedoverburden sampler Figures 1 and 2 is then attached to the hollow drillrods 43 which pass through the chuck 38 and the Kelly stem 40 of thedrill rig. The sampling device is lowered to the bottom of the hole 34,the drill rods clamped into the chuck 38 and a downward pressure exertedby hydraulic cylinders 4| which is transmitted by the hollow drill rods43 to the sampling device. Rotary motion is imparted to the samplingdevice by the rotary table 39 via the Kelly stem 40 and the hollow drillrods 43. As soon as downward thrust and rotation are imparted to thesampling device the slushpump 59 is put in operation. The pump 50 picksup the drilling fluid 38 from the tank 48 by means of intake 49 andforces it through hose 46 to water swivel 44 and thence through thehollow drill rods 43 to the sampling device. The drilling fluid 36enters and passes through the sampling device as shown by enlargedFigure 4 and escapes by rising upward in the hole 34 in the overburden35, through the casing 33 to the overflow trough 41 and thence back totank 48.

As the sample 31 enters the sample tube 21 of the sampling device, thedrilling fluid 36 entrapped therein when the sampling device is loweredto bottom of the hole 34, which is kept full of drilling fluid 36 at alltimes, vents into the hole 34 as shown in Figures 3 and 4, by arrows.

The drill rig shown in Figure 3 is of the truck 3lmounted type, equippedwith a folding mast 42 to permit hoisting of the tool by means of line45.

I am aware that prior-to my invention double core barrels connected by abearing swivel have been used for coring rock. I therefore do not claimsuch a, combination broadly; but I claim:

An undisturbed soil sampling apparatus comprising a drill barrel, adrill head at one end of the barrel and a drilling shoe at the other, acore barrel within the drill barrel, said barrel including a.displaceable liner for facilitating removal of the core adapted to beformed in said liner, means associated with the core and drill barrelsfor hydraulically removing drill cuttings and loose material from theoperating zone of the drilling shoe, means connecting the barrels so asto permit the drill barrel to be rotated relative to. the core barrel,said means including a passage establishing communication between theinterior of the core barrel and conduits formed in the drill head andopening to its exterior, valve means within the upper portion of "thecore barrel, said valve means being normally closed but operable toefl'ect communication between the space below said valve means and thelower end of said passage, whereby fluid entrapped in the core barrelwill be vented to the exterior of the drill barrel without exposure tothe pressure of the circulating drill fluid, means in connection withsaid barrel head for simul- 6 taneously imparting movement to the drillbarrel and a downward soil penetrating movement to the core barrel; andmeans in connection with l the lower end of the core barrel and enacting'5 with said barrel to seal the interior of the barrel against theentrance of the drilling fluid.

HENRY L. JOHNSON.

